Packer retrieving tool



Oct. 29, 1963 w. T. LEE ETAL' PACKER RETRIEVING TOOL 2 Sheets-Sheet 1Filed Jan. 2, 1959 James L. /Ve wman ATIO/PNEY Oct. 29, 1963 w. T. LEEETAL 3,108,637

PACKER RETRIEVING TOOL Filed Jan. 2, 1959 2 Sheets-Sheet 2 w QM:

- 5 W////am 7: Lee

z/ameJ Z. Newman INVENTORS ATTORNEY United States Patent 3,108,637PACKER RETREVING TOOL William T. Lee, Dean W. Osmun, and James L.Newman, Houston, Tex assignors to Bowen-Itco, Inc., Houston, Tom, acorporation of Texas Filed Jan. 2, 1959, Ser. No. 784 ,74? 4 Claims.(Cl. 166-99) This invention relates to a packer retrieving device andmore particularly to a tool for releasing and removing a packer from theinterior of a well casing tubing, or the like.

In the production and operation of oil and gas wells, it is oftennecessary to pack off or seal the annulus between the well casing andtubing, or operating string, at some desired location for the punpose ofwithdrawing fiuid from the well at a predetermined depth or from aspecific zone of the formation which the well penetrates. For thispurpose it is customary to introduce into the casing, attached to thestring of drill pipe, tubing, or production string, a packer assemblywhich is adapted to be anchored in the casing at the desired level bymanipulation of such a string to seal oif the annulus. Such packermechanism may also be introduced into the Well and set therein in someother conventional manner.

Well packer equipment of this kind is sometimes designed to be left inthe well when the string is withdrawn, but frequently is constructed tobe released and removed with the string. Under some conditions, such asWhere it is desired to anchor the packer in the wells against bothupward and downward movement, or in the event of sticking of the packeror failure of the releasing mechanism, it becomes impossible to releasethe packer, so that it is then necessary to drill or cutaway theanchoring mechanism in order to recover the packer.

In the releasing of stuck packers, it has been customary heretofore tomake use of a milling tool or cutter of tuibular shape adapted to belowered into the well attached to the lower end of an operating stringand rotated in engagment with the anchoring mechanism or slips of thepacker to mill away the slips and release the packer. Such tools may beprovided with a central mandrel extending downwardly beyond the lowerend of the cutter and which is shaped to be extended into the tubularinner support of the packer assembly to centralize and hold the cutterin a centered position in the well during the cutting operation.

One difficulty often encountered in the use of packer releasingapparatus of this kind is that upon the drilling away and releasing ofthe anchoring mechanism of the packer, the parts of the packer thusfreed fall to the bottom of the well, making it necessary to carry outcostly fishing operations to clear the well before further drilling orproduction operators can be resumed.

The present invention has for an important object the provision ofpacker retrieving apparatus for use in wells embodying means forreleasing the packer by cutting away the anchoring slips of the packerassembly, and including means for holding the assembly against fallingin the well and by which the packer assembly may be retrieved with theoperating string.

Another object of the invention is to provide packer retrievingapparatus of the kind referred to having means for holding the parts ofthe packer assembly in assembled relation when the assembly has beenreleased and whereby the assembly may be removed from the well in anassembled condition.

A further object of the invention is the provision of packer retrievingapparatus embodying cutter means adapted to be lowered into a well on anoperating string and rotated therein to cut away the anchoring slips ofa packer assembly to release the same, and including catch- 3 ,lh8,637Patented Get. 29, 1%63 ice ing mechanism positioned to hold the packerassembly against falling in the well, and which may also be actuated topermit withdrawal of the mechanism from the well in the event that thepacker assembly cannot be released.

Another object of the invention is to provide packer retrievingapparatus including a central mandrel adapted to be attached to thelower end of an operating string in position to be extended through apacker assembly in a well and a cutter carried by the string forrotation therewith, the apparatus also embodying means carried on themandrel in position for engagement with the packer assembly to hold theassembly against downward movement in the well when released and whichis operable by rotation of the mandrel in the same direction as thedirection of rotation of the cutter to place the apparatus in conditionto be withdrawn from the assembly to leave the assembly in the well.

The above and other important objects and advantages of the inventionmay best be understood from the following detailed description,constituting a specification of the same, when considered in conjunctionwith the annexed drawings, wherein- FIGURE 1 is a fragmentary, vertical,central, crosssectional, somewhat diagrammatic view, on a reduced scale,illustrating the invention and showing the retrieving device insertedthrough a packer assembly in a well tubing or casing preparatory to thecarrying out of a packer releasing operation;

FIGURE 2 is a side elevational view, partly in crosssection, showingdetails of construction and the arrangement of the parts of theretrieving tool in its retracted or inactive condition and with theresilient fingers locking the mandrel against rotation;

FIGURE 3 is a view similar to that of FIGURE 2 showing the tool of theinvention in its catching or expanded condition and with the resilientfingers in a released non-locking position;

FIGURE 4 is a cross-sectional view, on an enlarged scale, taken alongthe line 44 of FIGURE 3, looking in the direction indicated by thearrows; and

FIGURE 5 is a cross-sectional view, on an enlarged scale, taken alongthe line 5-5 of FIGURE 3.

Referring now to the drawings in greater detail, the invention isillustrated herein in connection with its use in the retrieving ofpacker assemblies from oil wells having a well casing or tubing, such asthat shown at T in FIG- URE 1, in which a packer assembly P ofconventional design is anchored, as by means of upper and lower slipmechanisms S and S. Packer mechanism of this type is commonly introducedinto the casing or tubing attached to a tubular production string andanchored at the desired location by manipulation of the string. Suchpacker mechanism is provided with a central tubular mandrel or body B,and when anchored is usually left in the well upon removal of theproduction string.

In the event that it is desired to remove the packer assembly from the'well, it is customary to release the assembly by milling away theanchoring slips S and S by the use of tubular cutting tools ofappropriate design lowered into the well on an operating string. Thereleasing of packer mechanism in this manner is, however, attended bythe danger that the assembly, or some of its parts may fall in the Welland become stuck at some lower level therein or come to rest at thebottom of the well, necessitating expensive and time consuming fishingoperations in order to recover the parts before further drilling orother operation of the well can be accomplished. It is for the purposeof preventing the falling of the packer assembly or its parts whenreleased that the present invention has been designed.

In the present illustration the invention comprises an inner tubularmandrel, stinger, or inner part 10, which is externally threaded at itsupper end portion for attachment to the lower end of the lowermostsection 12 of a tubular operating string of pipe, generally designated14, and provided at its lower end with an externally enlarged guide andactuator portion 16.

An outer generally tubular part or support member 18 is mounted on theinner part or mandrel it in surrounding relation thereto and for limitedlongitudinal and rotational movement relative to the inner part. Thisouter part 1% may conveniently be formed of upper and lower sections 29and 22 threadably connected together as indicated at 24, the uppersection being provided with an internal coarse square or buttress thread26, which is threadably engageable with a similar external thread 28 onthe inner part, to impart limited relative longitudinal movement to theparts upon relative rotation of the parts. The inner part is alsoprovided with an insert 36, positioned in an external longitudinalrecess 32 and which extends outwardly beyond the recess, in position forengagement with an inwardly extending stop element 34 to limit left handrotation of the mandrel in the outer part. The stop member 3% may beremovably secured to the inner part, as by means of screws 36, or thelike.

At its upper end, the upper section 2:) is formed with an externallyreduced portion 38, which fits into a lower end recess 49 in a fitting 42, whose upper end portion is internally threaded for connection withthe lower external portion 44 of the lowermost section 12 of theoperating string, whereby substantial clearance, as best seen at 46 inFIGURE 4, is provided between the external surface of the portion 33 andthe inner wall of the recess to allow the outer part to rotate relativeto the fitting.

The upper section 20 also carries friction elements 48 which may takethe form of leaf springs, secured to the upper section at their lowerends, as by means of screws 50, and whose upper end portions 54!- extendupwardly into the recess 40 between the external surface of the portion38 and the internal Wall of the recess so that when one or more of suchend portions 54 extends into one or more of such recesses 40 the sleeve20 is locked to the mandrel to prevent relative rotation (FIG. 2).Suitable means, such as the coil spring 56, is positioned about theinner part whose upper end bears against the lower end of the lowermostsection 12 of the operating string and whose lower end is seated on theupper end of the upper section of the outer part to yieldingly hold theouter part against upward movement relative to the inner part.

The lower section 22 of the outer part is longitudinally slotted toprovide downwardly extending flexible packer supporting fingers or catchmeans 58, whose lower end portions are internally and externallythickened, as indicated at 60, to provide abutment portions positionedfor engagement with the actuator portion 16 of the inner part to expandthe fingers upon downward movement of the outer part relative to theinner part to the position illustrated in FIGURE 3. The actuator portion16 of the inner part is formed with an upwardly facing annular shoulder62, positioned for engagement with the end faces of the enlarged lowerend portions 65 of the fingers to limit downward movement of the outerpart relative to the inner part, and above the shoulder 62, the actuatorportion, is formed with an upwardly and inwardly tapering external face64, positioned to be engaged by the inner bevelled faces 66 of theenlarged lower end portions of the fingers to expand the fingersradially outwardly upon downward movement of the outer part relative tothe inner part. As its lower end, the lower end enlargement 16 of theinner part may have an external, bevelled, guide face 68. The internallyand externally thickened lower end portions 60 of the fingers 58 arealso provided with upper and lower external bevelled faces 70 and 72,for a purpose to be hereinafter pointed out.

In making use of the retriever mechanism constructed and arranged asdescribed above, the device is connected to the lower end of thelowermost section 12 of the operating string, as illustrated in FIGURES2 and 3, the parts being normally in the positions illustrated in FIGURE3, and the upper end of the section 12 is threadably connected to thenext section of the string above as by means of coupling element 74,having an externally threaded lower end portion 76 to which the upperend of the tubular cutter or milling tool 78 is connected in surroundingrelation to the section 12 and which tool is provided with lower endcutting teeth 80 positioned for engagement with the anchoring mechanismS, S of the packer assembly to mill away the anchoring mechanism andrelease the packer assembly upon rotation of the milling tool inengagement therewith. With the retrieving mechanism thus assembled andconnected to the operating string, the retriever mechanism is lowered inthe well to extend the inner and outer parts of the retriever mechanismdownwardly through the tubular body B of the packer assembly, so thatthe section 12 of the operating string may be extended through the bodyto permit the milling tool 78 to be engaged with the anchoring mechanismof the packer assembly to mill away the upper anchoring mechanism S uponrotation of the operating string.

During the lowering of the retriever mechanism with the fingers 58 inexpanded positions, as illustrated in FIGURE 3, the lower externalbevelled faces 72 of the fingers will engage the upper end of the body Band the inner part will be moved downwardly relative to the outer partagainst the resistence of the spring 56, permitting the inner bevelledfaces 66 of the fingers to move upwardly and inwardly along the taperingface 64 of the actuator to permit the fingers to be contracted radiallyinwardly, as illustrated in FIGURE 2, to allow the mechanism to passthrough the body. When the mechanism is lowered sufficiently so that theleaf springs 48 enter the bore of the body B, they are retracted fromtheir locking position (FIG. 2) to their non-locking position (FIG. 3)and stay in such non-locking position until the fingers 43 pass belowthe body B at which time they return to the locking position of FIG. 2.As soon as the retriever mechanism has passed downwarly through thebody, the spring 56 will cause the outer part to again move downwardlyrelative to the inner part to the catching position illustrated inFIGURE 3 (but with the spring 48 in the locked position of FIG. 2) tore-expand the fingers into positions for engagement with the lower endof the body B to hold the packer assembly against downward movement inthe well when the anchoring mechanism of the assembly has been released.

After the completion of the milling operation to release the upperanchoring mechanism S of the packer assembly, the lower anchoringmechanism S may be released by upward movement of the body B with theoperating string, and the packer assembly may be withdrawn from the wellwith the operating string, the faces of the lower end enlargements 60 ofthe fingers 58 being engageable with the lower end of the packerassembly to cause the packer assembly to move upwardly with the string.

In the event that it should be impossible to release the packerassembly, or the packer assembly should become stuck in the well afterhaving been released, and it should be desired to withdraw the retrievermechanism, then the retriever mechanism may be moved upwardly into thebody B to engage the friction elements 48 with the internal wall of thebody, whereupon the operating string may be rotated to rotate the innerpart relative to the outer part, to engage the threads 26 and 28, tocause the outer part to move upwardly relative to the inner part againstthe resistance of the spring 5-6, to move the fingers 58 upwardlyrelative to the actuator portion of the inner part, to allow the fingersto move radially inwardly to their retracted positions, whereupon theretriever mechanism may be withdrawn upwardly through the body B andrecovered with the operating string leaving the packer assembly in thewell.

When the outer part has been moved upwardly on the mandrel, by rotationof the mandrel relative to the outer part, as described above, thefingers 58 will be out of catching position, and if it should then bedesired to reinsert the retriever mechanism through the packer assembly,this may be done by lowering the operating string to move the retrievermechanism into the body B until the friction elements 48 are inengagement with the internal surface of the body, whereupon the mandrelmay again be rotated while the outer part is held stationary to move theactuator 64 into engagement with the fingers 58 to expand the fingers tocatching positions, after which the mandrel may be moved downwardlythrough the body B to again engage the cutter 7 8 with the anchoringmechanism to continue the milling away of the anchoring mechanism,should this be necessary.

It will be noted that the external thread 28 of the mandrel is not quitein engagement with the internal thread 26 of the outer part or cage whenthe lower ends of the fingers 58 are shouldered on the shoulder 62 ofthe mandrel, as shown in FIGURE 3, and the key or stop member 30 ispositioned to limit the rotation of the mandrel to the right in andrelative to the outer part 18 to prevent the threads from binding, sothat the parts are prevented from becoming stuck in catching positionand are always in condition to be moved to retracted or releasingposition by relative rotation of the parts with the friction elements 48in engagement with the internal wall of the body B.

For satisfactory functioning of the apparatus, it is necessary that thecoil spring 56 be of suflicient strength to move the outer part intocatching position, as seen in FIGURE 3 against the frictional resistanceof the elements 48 when the latter are in contact with the inner wall ofthe body B, while at the same time the friction elements 48 must exertsuflicient force against the inner wall of the body Bto hold the outerpart against rotation to permit the mandrel to be rotated to move theouter part to releasing position against the resistance of the coilspring.

It will thus be seen that the invention constructed and operated in themanner described above provides a retrieving tool which is of ruggedconstruction; which may be used to recover a packer assembly from a welltubular casing; which is effective to prevent accidental loss of theparts of the packer assembly when released, and which may be recoveredintact in the event that the packer assembly cannot be recovered withthe tool from the well.

The invention is disclosed herein in connection with a certain specificembodiment of the same, but it will be understood that this is intendedby way of example only, and that numerous changes can be made in theconstruction and arrangement of the various parts, within the spirit ofthe invention and the scope of the appended claims.

Having thus clearly shown and described the invention, what is claimedas new and desired to secure by Letters Patent is:

1. Apparatus for retrieving from a well a packer assembly having acentral opening therethrough, comprismg:

(a) a tubular mandrel adapted to be connected at one end to a tubularoperating string for lowering in a well to extend the mandrel throughsaid opening;

() an internally threaded sleeve surrounding and movably mounted on themandrel for longitudinal movement thereon;

(c) flexible catch fingers connected to said sleeve for lateral flexingmovement toward and away from the mandrel;

(d) expander means connected to the mandrel for coaction with said catchfingers in a longitudinal catching position to flex said fingers awayfrom the mandrel to position said fingers for engagement with the lowerend of said assembly to support the assembly against downward movementrelative to the mandrel;

(e) yieldable means positioned for coaction with the mandrel and sleeveto yieldingly urge said sleeve toward said catching position;

(1) said fingers being extended for engagement with the upper end ofsaid assembly when in said catching position to resist downward movementof the sleeve and to retract said fingers for passing same downwardlywith said mandrel through said opening;

(g) and release means for releasing said catch fingers from saidcatching position to a retracted position;

(h) said release means including:

\(1) friction elements on said sleeve and urged radially outwardly forengagement with the wall of said central opening;

(2) external threads on said mandrel threaded in engagement with saidinternal threads on said sleeve;

(3) the convolutions of said external threads being spacedlongitudinally a greater distance than the width of the internal threadson said sleeve to enable said sleeve to move longitudinally withoutrotation to the extent of such spacing.

2. Apparatus for retrieving from a well a packer assembly having acentral opening therethrough, comprismg:

(a) a tubular mandrel having a portion with external threads thereon andadapted to be connected at one end to a tubular operating string forlowering in a "well to extend the mandrel through said opening;

([2) an internally threaded sleeve surrounding said mandrel in threadedengagement with said external threads and having the threads on themandrel and the sleeve longitudinally spaced with respect to each otherfor longitudinal movement thereon;

(c) flexible catch fingers connected to said sleeve for lateral flexingmovement toward and away from the mandrel;

(d) expander means connected to the mandrel for coaction with said catchfingers in a longitudinal catching position to flex said fingers away:from the mandrel to position said fingers for engagement with the lowerend of said assembly to support the assembly against downward movementrelative to the mandrel;

(e) yieldable means positioned for coaction with the mandrel and sleeveto yieldingly urge said sleeve toward said catching position;

(f) said fingers being extended for engagement with the upper end ofsaid assembly when in said catching position to resist downward movementof the sleeve and to retract said fingers for passing same downwardlywith said mandrel through said opening; and

(g) releasable lock means on said sleeve and connected for locking saidsleeve to said mandrel for preventing relative rotation between saidsleeve and said mandrel when said fingers are in the catching positionto prevent inadvertent releasing of said fingers from the catchingposition.

3. Apparatus for retrieving from a well a packer assembly having acentral opening therethrough, comprismg:

(a) a tubular mandrel having a portion with external threads thereon andadapted to be connected at one end to a tubular operating string forlowering in a well to extend the mandrel through said opening;

(b) an internally threaded sleeve surrounding said mandrel in threadedengagement with said external threads and having the threads on themandrel and the sleeve longitudinally spaced with respect to each otherfor longitudinal movement thereon;

(c) flexible catch fingers connected to said sleeve for lateral flexingmovement toward and away from the mandrel;

(d) expander means connected to the mandrel :for coaction with saidcatch fingers in a longitudinal catching position to flex said fingersaway from the man drel to position said fingers for engagement with thelower end of said assembly to support the assembly against downwardmovement relative to the mandrel;

(e) yieldable means positioned for coaction with the mandrel and sleeveto yieldingly urge said sleeve toward said catching position;

(1) said fingers being extended for engagement with the upper end ofsaid assembly when in said catching position to resist downward movementof the sleeve and to retract said fingers for passing same downwardlywith said mandrel through said opening;

g) friction elements having their [lower portions connected to saidsleeve but having their upper portions free to move radially inwardlyand outwardly; and

(/1) a locking sleeve connected to said mandrel and having a recesstherein for receiving the upper end of at least one of said frictionelements when extended outwardly for thereby locking said threadedsleeve to said mandrel for preventing relative rotation therebetween butreleasable from such locking position by an inward movement of saidfriction element.

4. Apparatus for retrieving from a well a packer assembly having acentral opening therethrough, comprising:

(a) a tubular mandrel having a portion with external threads thereon andadapted to be connected at one end to a tubular operating string forlowering in a well to extend the mandrel through said opening;

(b) an internally threaded sleeve surrounding said mandrel in threadedengagement with said external threads and having the thread on themandrel and the sleeve longitudinal spaced with respect to each otherfor longitudinal movement thereon;

(c) flexible catch fingers connected to said sleeve for lateral flexingmovement toward and away from the mandrel;

(a') expander means connected to the mandrel for coaction with saidcatch fingers in a longitudinal catching position to flex said fingersaway from the mandrel to position said fingers for engagement with thelower end of said assembly to support the assembly against downwardmovement relative to the mandrel;

(e) yieldable means positioned for coaction with the mandrel and sleeveto yieldingly urge said sleeve toward said catching position;

(1) said fingers being extended for engagement with the upper end ofsaid assembly when in said catching position to resist downward movementof the sleeve and to retract said fingers for passing same downwardlywith said mandrel through said opening;

g) and release means for releasing said catch fingers from said catchingposition to a retracted position;

(It) said release means including:

(1) friction elements on said sleeve and urged radially outwardly forengagement with the wall of said central opening;

(2) external threads on said mandrel threaded in engagement with saidinternal threads on said sleeve;

(3) the convolutions of said external threads eing spaced longitudinallya greater distance than the width of the internal threads on said sleeveto enable said sleeve to move longitudinally without rotation to theextent of such spacing;

(i) said friction elements having their upper ends movable inwardly andoutwardly;

(j) a locking sleeve connected to said mandrel and having a recesstherein for receiving the upper end of at least one of said frictionelements when extended outwardly for thereby locking said threadedsleeve to said mandrel for preventing relative rotation therebetween butreleasable from such locking position by an inward movement of saidfriction element.

References Cited in the file of this patent UNITED STATES PATENTS688,543 Petit Dec. 10, 1901 1,715,481 Ventresca June 4, 1929 1,765,864Corey June 24, 1930 2,067,885 Brown Jan. 19, 1937 2,106,235 Brown Jan.25, 1938 2,149,417 Brown Mar. 7, 1939 2,449,841 Claypool et a1 Sept. 21,1948 2,481,637 Yancey Sept. 13, 1949 2,487,456 Lowrey Nov. 8, 19492,577,605 Clayton Dec. 4, 1951 2,657,907 Cochran et al. Nov. 3, 19532,683,492 Baker July 13, 1954 2,804,148 Schrempt et al. Aug. 27, 19572,882,015 Beck Apr. 14, 1959 2,904,114 Webb et al. Sept. 15, 19593,005,493 Crowe et al. Oct. 24, 1961

1. APPARATUS FOR RETRIEVING FROM A WELL A PACKER ASSEMBLY HAVING ACENTRAL OPENING THERETHROUGH, COMPRISING: (A) A TUBULAR MANDREL ADAPTEDTO BE CONNECTED AT ONE END TO A TUBULAR OPERATING STRING FOR LOWERING INA WELL TO EXTEND THE MANDREL THROUGH SAID OPENING; (B) AN INTERNALLYTHREADED SLEEVE SURROUNDING AND MOVABLY MOUNTED ON THE MANDREL FORLONGITUDINAL MOVEMENT THEREON; (C) FLEXIBLE CATCH FINGERS CONNECTED TOSAID SLEEVE FOR LATERAL FLEXING MOVEMENT TOWARD AND AWAY FROM THEMANDREL; (D) EXPANDER MEANS CONNECTED TO THE MANDREL FOR COACTION WITHSAID CATCH FINGERS IN A LONGITUDINAL CATCHING POSITION TO FLEX SAIDFINGERS AWAY FROM THE MANDREL TO POSITION SAID FINGERS FOR ENGAGEMENTWITH THE LOWER END OF SAID ASSEMBLY TO SUPPORT THE ASSEMBLY AGAINSTDOWNWARD MOVEMENT RELATIVE TO THE MANDREL; (E) YIELDABLE MEANSPOSITIONED FOR COACTION WITH THE MANDREL AND SLEEVE TO YIELDINGLY URGESAID SLEEVE TOWARD SAID CATCHING POSITION; (F) SAID FINGERS BEINGEXTENDED FOR ENGAGEMENT WITH THE UPPER END OF SAID ASSEMBLY WHEN IN SAIDCATCHING POSITION TO RESIST DOWNWARD MOVEMENT OF THE SLEEVE AND TORETRACT SAID FINGERS FOR PASSING SAME DOWNWARDLY WITH SAID MANDRELTHROUGH SAID OPENING; (G) AND RELEASE MEANS FOR RELEASING SAID CATCHFINGERS FROM SAID CATCHING POSITION TO A RETRACTED POSITION; (H) SAIDRELEASE MEANS INCLUDING: (1) FRICTION ELEMENTS ON SIAD SLEEVE AND URGEDRADIALLY OUTWARDLY FOR ENGAGEMENT WITH THE WALL OF SAID CENTRAL OPENING;(2) EXTERNAL THREADS ON SAID MANDREL THREADED IN ENGAGEMENT WITH SAIDINTERNAL THREADS ON SAID SLEEVE; (3) THE CONVOLUTIONS OF SAID EXTERNALTHREADS BEING SPACED LONGITUDINALLY A GREATER DISTANCE THAN THE WIDTH OFTHE INTERNAL THREADS ON SAID SLEEVE TO ENABLE SAID SLEEVE TO MOVELONGITUDINALLY WITHOUT ROTATION TO THE EXTENT OF SUCH SPACING.